Patent Literature 1 discloses a semiconductor device having an island and a semiconductor element bonded on the island, the island and the semiconductor element being encapsulated in a resin. In this semiconductor device, an electrically conductive layer having an electromagnetic wave shielding function is formed on a surface of the encapsulation resin or in the resin to reduce the influence of external electromagnetic wave noise. Further, the electrically conductive layer and the island are connected to each other to enable heat conduction between the electrically conductive layer and the island and dissipation of heat from the electrically conductive layer.